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本文研究了不同Cd2+浓度与不同温度交互作用对中国海洋大学微藻种质库(MACC)保存的小球藻(Chlorellasp.)、微绿球藻(Nannochloris oculata)和杜氏盐藻(Dunaliella salina)的叶绿素荧光参数(PSII的最大光化学量子产量Fv/Fm、PSII的实际光能转化效率Yield、光化学淬灭qP和非光化学淬灭NPQ)、叶绿素相对含量以及细胞密度的影响。结果表明,随着Cd2+浓度的升高,3株微藻的主要荧光参数、叶绿素相对含量和细胞密度均呈明显下降趋势。但微绿球藻的荧光参数Fv/Fm在对照组与10μmol/LCd2+浓度时基本一致,这可能与低浓度Cd2+在一定程度上刺激了微藻生长有关。相关性分析结果表明,3株微藻荧光参数Fv/Fm和Yield均与Cd2+浓度呈极显著的负相关,小球藻和微绿球藻的叶绿素相对含量和细胞密度与Cd2+浓度呈显著的负相关,杜氏盐藻的叶绿素相对含量和细胞密度在48h后与Cd2+浓度呈显著的负相关,随着Cd2+浓度的增加而降低。多重比较结果表明,小球藻在25℃时对Cd2+的耐受性最强,该温度下荧光参数(Fv/Fm和Yield)、细胞密度和叶绿素相对含量显著高于20℃与30℃处理组。与20℃和25℃相比,在30℃时微绿球藻对Cd2+更加敏感,各荧光参数值均较低,细胞密度和叶绿素相对含量明显下降。杜氏盐藻在25℃时对Cd2+的耐受性最强,15℃与35℃温度条件下,各参数均明显下降,表明不适合的温度会增加重金属Cd2+的胁迫作用。本文还初步探讨了叶绿素荧光技术在重金属与环境因子联合胁迫研究中的应用。
In this paper, we studied the effects of different concentrations of Cd2 + on the temperature of Chlorellasp., Nannochloris oculata and Dunaliella salina stored in the microalgal bank (MACC) of Ocean University of China Chlorophyll fluorescence parameters (the maximum photochemical quantum yield of PSII Fv / Fm, the actual yield of PSII Yield, photochemical quenching qP and non-photochemical quenching NPQ), the relative content of chlorophyll and cell density. The results showed that with the increase of Cd2 + concentration, the main fluorescence parameters, the relative content of chlorophyll and the cell density of three strains of microalgae all decreased obviously. However, the fluorescence parameter Fv / Fm of Micrococcus luteus was basically the same as that of 10μmol / L Cd2 + in the control group, which may be related to the fact that low concentration of Cd2 + stimulated the growth of microalgae to a certain extent. Correlation analysis showed that the fluorescence parameters Fv / Fm and Yield of the three strains of microalgae showed extremely significant negative correlation with Cd2 + concentration. The relative contents of chlorophyll and cell density of Chlorella vulgaris and Chlorococcum sp. Were significantly negative with Cd2 + concentration , The relative contents of chlorophyll and cell density of Dunaliella salina were negatively correlated with Cd2 + concentration at 48h, and decreased with the increase of Cd2 + concentration. The results of multiple comparisons showed that Chlorella was the strongest tolerant to Cd2 + at 25 ℃, and the fluorescence parameters (Fv / Fm and Yield), cell density and relative chlorophyll content were significantly higher than those at 20 ℃ and 30 ℃ . Compared with 20 ℃ and 25 ℃, Microcystis aeruginosa was more sensitive to Cd2 +, lower fluorescence parameters and relative decrease of cell density and chlorophyll content at 30 ℃. Dunaliella salina was the strongest tolerant to Cd2 + at 25 ℃. Under the conditions of 15 ℃ and 35 ℃, the parameters of Dunaliella salina decreased significantly, indicating that the inappropriate temperature would increase the stress of heavy metal Cd2 +. This article also initially discussed the application of chlorophyll fluorescence technology in the joint stress of heavy metals and environmental factors.